Communications and Networks
A computer network, is simply a network of interconnected computers. The network allows the computers inside it to communicate with each other and share information and resources. When a computer sends information to another computer through a network, the information chopped up into little bits called packets, the router reads the packets before sending it to their destination where the packet is reassembled. Connectivity There are many ways to connect the computer to the world wide web, but the most used being wireless LAN, through optic fiber cables, or power line communication. Internet :Main article: Internet The internet, contrary to popular belief, is not the same as the world wide web, the internet is basically a huge global system of interconnected computer networks that uses the standardized internet protocol suite. The internet can also be called a network of networks, which are linked together using different connectivity methods. Types of connectivity Optical fiber cables Optical fiber are basically thin glass/plastic transparent rods which can transfer light. The advantage of using these cables is that the light does not leak out of the cable and is thus ideal for long distance communication. These cables are also used to deliver information. Wireless LAN LAN, or local area network is used to connect computers in a small area, like a home or office, using Ethernet cables or WIFI (these two methods being the most common), the computers in the same Local area network can send information and respond to each other. For example, in your home, your computer and printer may be connected in the same LAN through WIFI, so when you press print on your computer, the command to print is sent from your computer to the printer through the LAN and the printer prints. The advantage of LAN is that compared to other forms of networks, LAN is often the smartest because the area that the LAN covers is normally not very big, which means information travels at a much faster rate. HomePNA The computers in a LAN is most often connected using Ethernet cables. Power line communication Power line communication is a system in which data is is carried using a conductor in order to access the internet. This system involves using the main infrastructure (power grid), all the user has to do is purchase a router and he/she would be able to use the ordinary electricity lines to send information to and from the web. The advantage of such a system is that it is much faster than using WIFI access the web, as the information travels through wires, not the air, however it's main disadvantages is that the power line routers is a lot more expensive than the ordinary WIFI's router and is thus not as widely used by the public. World Wide Web The world wide web is the part of the internet that contains the webpages and websites. The internet is made up of servers, which contain the text,images and other files and things we see when we open a webpage. In simple words, the world wide web is a universe of network accessible information. How does the internet work A web browser is required to view web pages. Web browsers also support links to other documents as well as graphics, audio as well as video files. When we visit a webpage, our computer uses the web address we entered and locates the web site's server. The server than sends information back to our computer in the form of binary, since we don't understand binary, we need some sort of translator to translate the binary into text, images and other files, and the translator comes in the form of a web browser. What the web browser does is that it turns all the binary from the web into useful information we know. The most common web browser used include Microsoft's internet explorer, Mozilla Firefox, Safari and the most recent, Google chrome. Reference http://www.commoncraft.com/world-wide-web http://www.w3.org/WWW/ Images from: Power line image:http://www.imc.cce.i.kyoto-u.ac.jp/research/image/plc.png LAN image:http://www.internet-computer-checkup.com/image-files/wireless-lan-router.jpg